Conventionally known is a technique for detecting a state in which a user is not using a display device such as a television or a display and turning off the display thereof to save electric power.
For example, Japanese Patent Application Laid-open No. 2011-061300 discloses a technique in which display of a television is turned off depending on a detection state of a face of a user captured by a capturing module so as to prevent the continuous display of the television when it is not viewed and thus achieve electric power saving.
In addition, Japanese Patent Application Laid-open No. 2010-145765 discloses a technique in which a camera captures an image to detect the fact that a user is not seated at a given position and the display of a display screen is then turned off.
When the configuration for constantly detecting a state of a user is adopted to enable rapid shifting to an electric power saving mode, it is required that means for capturing an image of a user is constantly operating, which makes it difficult to reduce electric power consumption.